Device for folding a flap of a cardboard blank



A. FREI 3,168,017

DEVICE FOR FOLDING A FLAP OF A CARDBOARD BLANK Feb. 2, 1965 5 Sheets-Sheet l Fig/1.

A. FREI 3,168,017

DEVICE Foa FOLDING A FLAP oF A cARDBoARD BLANK Feb. 1965 3 Sheets-Sheet 2 Feb. 2, 1965 A. FREI 3,168,017

DEVICE FOR FOLDING A FLAP 0F A CARDBOARD BLANK Filed Sept. 20. 1962 3 Sheets-Sheet 3 United States Patent 3,168,017 DEVICE FR FOLDING A FLAP 0F A CARBBRD BLANK Arthur Frei, Les Pierrettes, St. Sulpice, Switzeriand,

assigner to i. Bobst and S011 SA., Prilly, near Lausanne, Switzerland, a corporation of Switzerland Filed Sept. 20, 1962, Ser. No. 224,927 Claims priority, application Switzeriand, Sept. 27, 196i, 11,261/ 61 7 Claims. (Cl. SiS- 49) This invention relates to folding devices of the type adapted to fold aps of cardboard elements.

In contrast to printing machines or presses working at a steady rhythm, folding machines employ guides, cams and other devices adapted to deflect from their trajectory the parts to be folded, while operating at a cadence depending on the passage of the pieces to be operated upon. It has already been proposed to make starting or stopping of certain functions dependent on the pieces to be folded themselves.

ln the device according to the present invention there is provided an elastically deformable part which is in an idle position outside the trajectory of the pieces to be folded, but is subject to the action of a member which by deforming it elastically, makes it penetrate into the said trajectory under the influence of a fluid, the action of which is controlled by a feeler detecting the passage of the pieces to be operated upon and acting in such a way that the elastically deformable part be held in the aforementioned trajectory when no piece to be operated upon is influencing the feeler and stays away from it in the opposite case. The feeler may be a mechanical element or may be a light ray which is intercepted case, it will be set in a place so as to make it possible for the folding to be suticiently initiated before the elastic member moves aside, in order to be for instance, terminated by a usual guide.

The annexed drawing shows an embodiment of the invention given by way of example, FIGS. 1 and 2 are respectively a side view, and a top view, diagrammatically shows the operation of the invention,

FIGS. 3 to 6 show in perspective, the successive phases of folding of a blank,

FIG. 7 is a half-diagrammatic top view of an embodiment of the device adapted to perform the folding shown in FIGS. 3 to 6,

FIG. 8 shows diagrammatically means for fixing the elements of the device,

FIG. 9 is a transverse sectional view through the machine, and

FIG. 10 is an end-view of a part of the device shown in FIG. 9.

The device shown in FIGS. 1 and 2 operates on a cardboard sheet 1, which is shifted in the direction of the arrow 2 by known means not represented, as for instance, conveying belts.

This sheet has a flap 3 adapted to be folded back onto the sheet 1, in the direction of the arrow 4 of FIG. 1. An elastic blade 5 raises the flap on its passage and, on the other hand, `a rigid guide 6 completes the folding when the sheet reaches position 1-3'.

It is evident that it is undesirable that blade 5 contact the sheet beyond the ap 3.

For this reason, this blade can occupy two positions, either the raised position shown in solid lines in FIG. 1, or its idle position 5. Due to its elasticity, the blade returns to it as soon as it is no longer raised by a small piston 7 moving in a tubular cylinder 8.

Thus, the problem to be resolved in this case is to raise the blade 5 during just the time necessary for the required raising of the flap 3 and not beyond that.

CII

lhli Patented Feb. 2, 1965 ICC FIG. 2 shows diagrammatically how this is managed by the action of the proper sheet i. At a judiciously chosen point of its trajectory is a roller-feeler 9 of an electric switch acting on piston 7, as denoted by the connection 16 drawn in dash-dotted line.

The switch in question should be chosen with great sensitiveness and little inertia. The current switched on or out by this latter will act on an electromagnetic valve of a known type, likewise with little inertia, making it possible for the compressed air to give rise to an overpressure in the cylinder S or, in opposition to this latter, to be emptied by putting it in communication with the surrounding air.

The piston '7 will not be in preference made of a rod and a piston but of a light rod of relatively small diameter only, being moved in a tube, this also with a view to making away, as far as possible, with the effects of inertia.

This provision is dictated by the high working speed liable to be required from the device which, independently of the irregularity or regularity of arrival of the successive sheets will carry out the expected folding in an impeccable manner.

If provision is made that, in effect, in the absence of a sheet to be folded the cylinder 8 remains under pressure while it is unloaded on the passage of a sheet, it is clear that by placing roller 9 as represented in the drawing, the blade 5 will be lowered as soon as it has exerted its function and will be lowered until the passage of the sheet end under roller 9, in order to resume the raised position on the arrival of the next sheet 11, whatever rnay be the distance which separates it from the previous one.

Thus, the device operates completely free from the rhythm governing the distribution of the sheets and, owing to its little inertia, at higher speeds.

FIGS. 3 and 7 show an example of folding a cut out cardboard piece in order to make a box with an automatic bottom. In the figures is shown one half of a piece only, the other half being similar to it with the exception of the lateral glueing flap 12.

Thus, there are, side by side, a simple iiap 13 and a double flap lily-14.

The iirst operation to be effected is to fold down the simple flap 13 on the piece, as shown in FIG. 4.

The second operation consists in folding the portion 14' of the double flap under portion 14, as shown in FIG. 5.

The third and last operation, before the conventional folding and glueing of the box, consists in folding back the double flap which has already been partially folded, into the plane of the sheet 1 as shown in FIG. 6.

In the folding-glueing machine, the cut but not folded cardboard piece is inserted between guides, as for instance 1S and 16 in FIG. 7 which it crosses downwards.

The folding of the two flaps 13 is carried out, for instance, at the beginning of the operation by known conventional means and it is in position A (FIG. 7) when said iiaps are folded down, that the sheets will reach one by one the folding device according to the present invention.

Belts 17, 18 and 19 transport the sheet.

At 20 are shown two elastic blades similar to blade 5 of FIGS. 1 and 2, which a piston 21 located above the plane of the advancing sheet will lower into the trajectory of the sheet to be folded, to cause blades Ztl to contact the flap portion 14. When contacting these blades, the iiap portions i4' will be folded down below the plane of the sheet, by an amount sufficient to permit them to be folded under the corresponding parts 14" when the deflected portions 14 subsequently contact fixed guides 22. From the moment their pressure on the blades 20, which, due to its elasticity, will resume itsposition above theV plane of the sheet and outside the trajectory of the sheet.

This release f the piston 21 is obtained by the contact with switch roller 23 of the edge of the folded down flap V13 on-the left of-Y the-.drawing -and v`will last .until the sheet hasv thoroughlypassedunder. that roller.

The connection between vthe roller` and pistons is indiycated symbolically bythe double dash-dotted linef24.

-in its trajectoryby pistonsZ, butthis 'time from below the plane of the sheet.

Consequently, the bladesZS raise the double flaps 1414 on their passage.

This action lasts untiltheselaps arrive under the series of rollers 27 whichcompletetheir folding, WhileV the pistons 26 release Vthe blades 25 which. arelowered under -the planeof `thezdrawing, .outside'..theztrajectory of the sheet.

The lowering of the. blades until the sheet has passed -will be brought about by the roller .28, a switch andthe Vcorresponding connectionZS?. The sheet is Aleft folded after this operation as indicated in. C.

Whatever may be the number of foldingsttobe carried out and of .the corresponding working stations, it appears Vthat all along the passage ofthe sheets .across the machine equipped in this way, the working'rhythm of 4all the successive folding devices is determined by the merefpassage of the sheets.

FIG. 8 shows means for supporting the elastic blade element.

This element isatube Si) on which is set a flange 31 with tightening screw 31.

This ange accommodates the cylinder 32, secured by means of a block 35 with tightening screw'36.

Another block '37 isfsupported in turn on stem 34 and can be immobilized by tightening screw-38 and supports `the elastic blade 39 against which piston 4th is acting. The

ail is let in at 41, preferably through a flexible hose 42.

The fixed guides, as well. as the rollers-of vthe switches or other feeler members `and electromagnetic control valves will be similarly supported.

.and the corresponding cylinder: and piston from a' single `two screws 33 and supporting on its turn a stem-34 by Finally, FGS. 9 and l0 show how it is possible to make p Y all these elements extremely'accessible by arranging all the'upper members on an oscillating frame.

At 43 and 44 are partially represented the longitudinal lateral parts of a folding glueing machine in which the three conveying belts 17, f3 and 19 of FIG. '7 'are visible.

Between the frame parts 43.- and 44 and under the belts, bars or tubes such as- 45Willfbe placed so as `to support the lower foldingmembers, forinstance blades 22, 25 and piston`26f of FIG. 7.

Above the belts -will be-supported similar'bars or tubes 46, bearing the upper folding members, suchfas blades 29, piston 2i, and rollers 23, 27 and 28 of FIG. 7.

However, these lbars-i6 are supportedfby a frame-.47 which in turn is supported by a beam 48 hinged atf49to a bracket 5) ofthe folding-glueing machine. Thefree end of the frame rests onV an opposite bracket 5l, to whichit can be xed by any locking means. 'The raised position of the beam "48, frame 47 and bars i6 is shown in chain dotted lines in PEG. 9.

The principal upper and lower tools will be' fixedftoV the bars along the axes 52 and 753 shown in dash-dottedr lines.

The raised position of the frame-and of the barsshows how the articulation of these elements makes their accessibility more easy and provides at the same access to the lower elements.

It is clear that the frame 47 could be completely tilted, for instance, at an angle. of so as to be placed horizontally beside the-machine.

One could Ialso fix onajpivotable frame the elements of the .device located underneaththe workingV plane, for instance, movableinthe sensejthat it could be lowered and pivoted within a horizontal plane.

Finally, it will be advantageous, yin order to-render the working of Ithedevicermore instantaneous, -to set the air control valves on end of the tubular cylinders, immediately behind the piston, so that the space to be emptied or filled .on each operationbe ofthe least possible volume.

What I claim. is:

l. Apparatusfor foldingaportion. of a blankrcomprisingmeans for advancingsaid blank insubstantially llat condition .along .a,determinable:; path, means operatively supported .Withirespect to said .path for :contacting said portion of .the blank. and deecting'the same, means located downstream offthe last .said means and yin thepath of theblank for engaging ,the portion thus deflected for folding the same and.- means supporting the means which deflects the portion ofthe blank tol move said means away from .the blankand free ofthe same as Said portion is engaged forv being folded, said means for dellecting .the

.portion of the blank including a flexible element and the vmeans supporting the latter :means including a'movably supported element. which is in contact lwith the flexible i element to: urge the same from a neutral position in which the flexible lelement liesoutside; the path of the-blank to a position in said-path to contact said portion.

2, Apparatus as claimed/in claim l comprising a feeler operatively positioned in-thefpath of the blank `for con- .tacting the blank toV sense passagethereof andmeans connecting thefeeler andmovable element to movethe same and the flexible element thereby to a position outside the .path of said blank.

3. Apparatus as claimed in lclaim 2 wherein said movable element is a piston the apparatus further comprising:

.-acylinder supporting said pistonand adaptedfor being zconnectedjto a hydraulic supply, as controlled'by .the

feeler, to move the piston.

4. Apparatus as claimed in claim 3.-wherein .said piston includes 'a' pistonr rod of substantially thesame diameter as said piston and adapted for contacting .the flexible element. Y

5. Apparatusas claimed in claim 3 comprising'a frame, means supporting said piston, cylinder :and liexibleelement from a commonsupport and meanssupporting'said common support for pivotal movement about said frame. 6. Apparatus as claimedin claim 5 .wherein saidA means for advancing said blank is located within said frame and said .common .support .is.locate d.above the means for advancing the blank.

7. Apparatus as claimed'in claim 3 comprising a frame,

:means supportingw said piston, cylinder and flexible. element from a common support, a frame, .saidmeans for advancing said blank being located within said .frame and ,means supporting said common -support below the means for Y advancin g. the blank.

VReferences Cited by thefExamner i UNITED STATES PATENTS 2,900,185 `s/59 :rare 27o-80X 2,962,945 12/60 Munch s .93-49 3,014,415 12/61 4rPierce s 93-49 FRANK E; BALEY, Pirmm'y Examiner. 

1. APPARATUS FOR FOLDING A PORTION OF A BLANK COMPRISING MEANS FOR ADVANCING SAID BLANK IN SUBSTANTIALLY FLAT CONDITION ALONG A DETERMINABLE PATH, MEANS OPERATIVELY SUPPORTED WITH RESPECT TO SAID PATH FOR CONTACTING SAID PORTION OF THE BLANK AND DEFLECTING THE SAME, MEANS LOCATED DOWNSTREAM OF THE LAST SAID MEANS AND IN THE PATH OF THE BLANK FOR ENGAGING THE PORTION THUS DEFLECTED FOR FOLDING THE SAME AND MEANS SUPPORTING THE MEANS WHICH DEFLECTS THE PORTION OF THE BLANK TO MOVE SAID MEANS AWAY FROM THE BLANK AND FREE OF THE SAME AS SAID PORTION IS ENGAGED FOR BEING FOLDED, SAID MEANS FOR DEFLECTING THE PORTION OF THE BLANK INCLUDING A FLEXIBLE ELEMENT AND THE MEANS SUPPORTING THE LATTER MEANS INCLUDING A MOVABLY SUPPORTED ELEMENT WHICH IS IN CONTACT WITH THE FLEXIBLE ELEMENT TO URGE THE SAME FROM A NEUTRAL POSITION, IN WHICH THE FLEXIBLE ELEMENT LIES OUTSIDE THE PATH OF THE BLANK TO A POSITION IN SAID PATH TO CONTACT SAID PORTION. 